Here is an idea for your heroes' quest rewards. I based it off of the Adventure Design Kit recommendation of 100-200 gold coins. In the first 14 quests, 200 is the most frequent amount, but there are a few in the range of 250-300, so I made 300 the upper limit. However, the later quest packs (elf, barbarian, etc) get pretty generous with the rewards, so the table below may be better suited to the earlier stages of a character's adventuring career.
Quest Reward Table
D20 gold coins
• 1. 110
• 2. 120
• 3. 130
• 4. 140
• 5 . 150
• 6. 160
• 7. 170
• 8. 180
• 9. . 190
• 10. 200
• 11 . 210
• 12. 220
• 13. 230
• 14. 240
• 15. 250
• 16. 260
• 17. 270
• 18. 280
• 19. 290
• 20 300